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   Hayley (hayley@social.applied-langua.ge)'s status on Tuesday, 12-Dec-2023 15:47:21 JST Hayley
   you mean to tell me that ice cream is not made of ice
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     iced depresso (icedquinn@blob.cat)'s status on Tuesday, 12-Dec-2023 15:47:13 JST iced depresso

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     @hayley i guess they're confused because snapshot could mean making a copy of everything (which, it does not do.)
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     Hayley (hayley@social.applied-langua.ge)'s status on Tuesday, 12-Dec-2023 15:47:18 JST Hayley

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     just checked with a book written by snooty compsci academics, snapshot at the beginning preserves objects that were live if you took a snapshot at the beginning
     
     ("D2/T2 mutations" refers to some examples of breaking concurrent GC earlier in the chapter, it makes sense in context)
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     iced depresso (icedquinn@blob.cat)'s status on Tuesday, 12-Dec-2023 16:01:44 JST iced depresso

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     @hayley i think its just the word snapshot that is messing with them. its used somewhat wrong in that "it means something else because i want it to" mathematician way
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     Hayley (hayley@social.applied-langua.ge)'s status on Tuesday, 12-Dec-2023 16:01:50 JST Hayley

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     • iced depresso
     @icedquinn there's a lot of incremental/copy-on-write systems which don't copy everything*, but that's possible. Maybe there's some cursed equivalence between SATB and CoW since tricolor and Cheney's algorithm have an equivalence in colours/cursors.
     
     *e.g. persistent data structures, fork(), incremental backups
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     iced depresso (icedquinn@blob.cat)'s status on Tuesday, 12-Dec-2023 16:03:25 JST iced depresso

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     • iced depresso
     @hayley like when knuth made up 'dynamic programming' and then later admitted it had no meaning he just sort of made it up to call it something.
     
     i remember having issues with how mathematicians often do this kind of shit to words and symbols. i don't anymore, but people go through that phase.
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     iced depresso (icedquinn@blob.cat)'s status on Tuesday, 12-Dec-2023 16:13:05 JST iced depresso

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     @hayley i mostly understand it as a weird way of saying "we just leave the colors painted between calls to the incremental GC"
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     Hayley (hayley@social.applied-langua.ge)'s status on Tuesday, 12-Dec-2023 16:13:06 JST Hayley

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     • iced depresso

     @icedquinn I thought about it for a bit and I think there is an argument that SATB does literally incrementally compute a snapshot by logging, though it’s more obvious in hybrid coalescing RC/SATB like Levanoni-Petrank and LXR where we’re logging the old values of fields/slots that we update. In pure SATB we only care for the old value to mark it before we update some location, so we mark it right before we update, processing the log entry immediately; coalescing RC needs to know both the old value and what location it came from in order to update refcounts, so we have to actually store the log.